The invention relates to an assembly of separable plastic components and members forming a supporting rack for a plurality of substantially identical metallic load units or subassemblies which require a protective translation device for cradling these units or subassemblies in their movement from one station or location to another, by means of a lift truck, motorized common carrier, and/or railroad car.
In the past, one type of transfer rack has been made of metal. Although the racks have been adequately supportive, they have not been as protective of their loads as is required. In some instances, elements of the load units or subassemblies have become displaced in relationship to their housings so that damage to the elements and the units has occurred. Exterior surfaces of the load units have been damaged by metal-to-metal contact with the supportive racks. Forming these racks out of steel has increased substantially the load weight which must be carried by trucks and railroad cars. Such added weight has of course been a severe burden not only in costs but also upon the energy requirements of the hauling power units, e.g., lift trucks and truck engines, and upon the locomotives pulling railroad cars containing these loads.
Another type of transfer rack which has met with limited use has been a vacuum-formed sheet of plastic material having cavities or recesses molded in the shape of the lower configuration of the load unit or subassembly to be carried by the rack. The problem arising in the use of this type of transfer rack has been the relative insecurity of load units or subassemblies seated in the cavities of a relatively thin fragile plastic sheet. The units have popped out of their recesses and been damaged by contact with other units on the rack, or on floor planes when they fell out of the rack entirely.
Losses in damaged load units or subassemblies and from high weight load transportation charges have been a significant factor in material handling costs. The instant invention was designed to provide one solution to this problem.